K.harsini Department of microbiology Syed ammal arts and science college Ramanathapuram

1. Amoebiasis
Medical microbiology
Presented by
k.harsini

2. Introduction
 Entamoeba histolytica are pathogenic amoeba causes the amoebiasis
What is amoeba?
 Primitive , Unicellular microbe
 It has a two stage
Trophozoites –active motile, feeding
Cyst –inactive , resistant, infective
 Multiply by binary fission.
 Some in soil and warm environment .
 Found in low oxygen & pressure

3.  Entamoeba histolytica physiology & structure
 Trophozoite
 Found in freshly passed stool
 Found in crypts of large intestine
 Fragile and can’t resist external environment
 cyst
 Formed stool
 Has four nuclei
 Resistant to strees

4.  Transmission
 Contaminated water and food (Faecal oral route)
 Epidemiology
 World wide distribution.
(mainly in India , china Mexico, Africa and south
america )
 High in tropic and subtropical
 Poor sanitation places –
asylums ,refugee camps,highly crowed area
 Homosexual population –
cutaneos amoebiasis

5. • Pathogenesis
•
• ➡️Ingestion
• ➡️Gastric acid stimulates releases of trophozoites in duedenum
• ➡️ divides causing necrosis in large intestine
• ➡️Tissue damage due to cytotoxins

6. Tissue damage
☞ attachment of trophozoites in host cell by galactose inhibitable
adherence
Protein
☞lysis of colonic epithelial cells, neutrophils, lymphocytes
,monocytes
☞alteration in cell permeability
☞ irreversible increase in calcium level
☞flask shaped ulceration

7. Clinical syndrom
intestinal amoebiasis
• Localized tissue destruction in large intestine
Abdominal, pain cramping and colitis with diarrhoea
• Sever bloody stool
Extra intestinal amoebiasis
• Liver affected hepatomegaly(mostly rightly lobe)
• Elevation of diaphragm
• Abscess formation
• Nausea
• Fever and chills

8. Lab diagnosis
Examinationof stool
Microscopic examination of stool
Serological testing
Lectin binding protein
Zymodeme analysis
Genome DNA analysis
Treatment
Drug: metronidazole
For asymptomatic:iodoquinol, paromycin

9. Prevention
• chlorination and filtration of water
Control
• Wash your hands and feeds
• Washing with water and soap
• Microbes are easily enter the nails and hair for the
presence of karotine regularly cut the nails
• Human feaces are use to fertilizer
• Proper disposal of drainage water
• Avoid the drinking of unbolied water

10. Thank you